import React, { Component } from 'react'

export default class Count extends Component {
  state = {}
  // 加法
  increment = () => {
      const {value} = this.selectNumber;
      this.props.jia(Number(value));
  }
  decrement = () => {
    const {value} = this.selectNumber;
    this.props.jian(Number(value));
  }
  // 奇数再加
  incrementIfOdd = () => {
    const {value} = this.selectNumber;
    if(this.props.count % 2 !== 0) {
      this.props.jia(Number(value))
    }
  }
  // 异步加
  incrementAsync = () => {
    const {value} = this.selectNumber;
    this.props.jiaAsync(Number(value), 500)
  }
  render() {
    console.log('ui',this.props);
    return (
      <>
        <h1>当前求和为: {this.props.count}</h1>
        <select ref={(c) => (this.selectNumber = c)}>
          <option value="1">1</option>
          <option value="2">2</option>
          <option value="3">3</option>
        </select>
        &nbsp;
        <button onClick={this.increment}>+</button>&nbsp;
        <button onClick={this.decrement}>-</button>&nbsp;
        <button onClick={this.incrementIfOdd}>当前求和为奇数再加</button>&nbsp;
        <button onClick={this.incrementAsync}>异步加</button>&nbsp;
      </>
    )
  }
}
